The Central Mojave Vegetation Polygons shapefile represents areas of the Mojave Desert classified into vegetation classes or alliances representative of the area from 1997-1999. The classification of these areas were derived from context gathered in the field data, photographs and additional satellite imagery that is not included in this data release. The original map coverage was preserved and released as a shapefile (mojave_veg_polygons.shp). In contrast to the Special Features Points vegetation classifications (described in the Special Features Points shapefile metadata record and ScienceBase item), the Central Mojave Vegetation Polygons were designated by vegetation alliances that extended 5 hectares or more. Map labels represent alliances and groups of alliances as described by the National Vegetation Classification, as it existed at that time. Each map unit is labeled by a primary land cover type and a secondary type where applicable. In addition, the source of data for labeling each map unit is also identified in the attribute table for each map unit. The metadata record (Mojave-Vegetation-Mapping_Mojave-Veg-Polygons-Metadata.xml), the Mojave vegetation polygons shapefile (zipped shapefile, mojave_veg_polygons.zip) and the label codes sheet that provides context for the vegetation classifications (LabelCodes.csv) are all included as attachments on the Mojave Vegetation Polygons ScienceBase item.